Are you talking about solar leases? This is where a company leases your roof for 15-20 years, puts their own solar panels on it, and then pays you a fraction of the proceeds.
Pros:
- no up front costs on your part
- no maintenance on your part
- steady (small) income
Cons:
- may make selling the home more complicated
- you won't make as much money as you would if you owned the panels
- may be more complicated to re-roof (likely there will be some part of your contract that covers this)